Physical Mechanism of Dual-Grounded Trielectrode Plasma Actuator

Abstract

To enhance the performance of a dielectric barrier discharge plasma actuator, a dual-grounded trielectrode plasma actuator, which has an electrically grounded and insulated third electrode on the alternating-current electrode, was suggested. In this research, the discharge structures, body force fields, and flowfield of the conventional dielectric barrier discharge plasma actuator and the dual-grounded trielectrode plasma actuator were investigated with a plasma simulation and a fluid simulation to clarify the performance improvement mechanism of the dual-grounded trielectrode plasma actuator. First, the validity of the simulation results was confirmed by comparing the results between the experiment and the simulation. Next, a detailed investigation of the plasma structures, the body force fields, and the flow velocity distributions was conducted. As a result, the following performance improvement mechanism was clarified. The body force generated near the alternating-current electrode edge effectively accelerated the flow. By putting the third electrode close to the alternating-current electrode edge, the plasma generated around the third electrode was supplied to the region near the alternating-current electrode edge, and the body force contributing to the flow acceleration was drastically enhanced. In addition, the vertical expansion of body force also contributed to the performance enhancement. The induced flow became thicker, and the rate of momentum loss by the friction force on the dielectric surface decreased.